1. Field of the Invention
The present invention relates to the field of microwave transmission lines and, more particularly, to an antenna lens array phase shifter for balanced microwave transmission lines.
2. Description of Related Art
State of the art phase array antennas need to be light weight and physically flexible for reusable deployment and stowage in a space and near-space environments. In some conventional dipole antenna arrays, power dividers couple each of the dipole antennas by unbalanced cables to a common transmit/receive point. Conventional unbalanced microwave transmission lines can include microstrip, waveguide, and coaxial transmission lines.
Conventional dipole antenna arrays often include conventional phase shifters having unbalanced line inputs/outputs such that additional circuitry is needed to transition, for example, to each of the balanced line dipole feeds. When using a conventional phase shifter with a balanced transmission line, a balanced-unbalanced (balun) transition is needed on the input side and the output side of the phase shifter as the balanced transmission line is coupled to both sides of the conventional unbalanced phase shifter. However, use of at least two baluns per conventional phase shifter for each antenna lens element pair results in increased size, weight and cost per element. As such, a need exists for a system and method for interfacing phase shifters to balanced transmission lines without the need for balun transitions.